Case Study 1 – Clinical Negligence
A 67-year-old man underwent a three-vessel coronary artery bypass graft operation and made an initial routine recovery. As per routine protocol, he was treated with a low-dose beta blocker and aspirin and low-dose subcutaneous heparin in the early postoperative period. On the third postoperative day, he experienced atrial fibrillation. An antiarrhythmic medication managed this, Amiodarone and normal sinus rhythm was restored by the fifth postoperative day.
He was discharged home on medications including Amiodarone and followed up in the outpatient clinic. He had no further symptoms of palpitation. He had routine examinations and ECG investigations on several occasions and was found to have a regular pulse and ECG trace with normal sinus rhythm. Three months postoperatively he had no history of palpitation and ECG confirmed normal sinus rhythm and the Amiodarone was discontinued. He remained on beta-blockade and aspirin medication. He remained in sinus rhythm on subsequent follow-ups.
The client complained that there was a failure in medical care as the open heart surgery had caused atrial fibrillation. We agreed that the open heart surgery had caused the atrial fibrillation. But we noted that atrial fibrillation was an accepted complication of open heart surgery, which occurs in more than 20% of cases. Typically such postoperative atrial fibrillation is prone to occur in the first week after open heart surgery and then becomes less likely and reverts to and remains in preoperative sinus rhythm.
Case Verdict – The Client Has No Claim
Full anticoagulation is not usually required. He was managed in an appropriate and standard manner so we saw no failure of duty of care in this case.
Case Study 2 – Personal Injury
A 70-year-old woman was driving a motor car involved in a head-on road traffic accident. She was wearing a seat belt and had a headrest. Airbags were deployed. The car was a write-off. Emergency services employed cutting gear to free her from the vehicle. She was taken by ambulance to the hospital and a CT scan showed an undisplaced fractured sternum. The transthoracic echocardiogram showed no abnormality. There was a mild elevation in cardiac enzymes.
She was monitored in the accident and emergency department and it was noted that she had episodes of fast atrial fibrillation on the ECG monitor. She was admitted to the hospital and observed and treated with analgesics. In the hospital 3 further episodes of atrial fibrillation were noted. A cardiology opinion was obtained and she was treated with a low-dose beta blocker oral medication. She was managed conservatively and after 6 days was discharged home on oral analgesic and beta-blocker medication.
On discharge home, she made a good recovery from the fractured sternum and the pain settled. However, she continued to experience palpitations with increasing frequency. Prior to the road traffic accident, she had never experienced palpitations and had never had a diagnosis of atrial fibrillation. She had non-insulin-dependent diabetes and an increased body mass index. Cardiologists introduced further antiarrhythmic and anticoagulant medication. Twelve months after the road traffic accident she was clinically stable and active in rate-controlled atrial fibrillation and antiarrhythmic and anticoagulant medications.
The client claimed that the atrial fibrillation had been caused by the road traffic accident and she had suffered because of this. The defendant suggested that (1) She may have had occult atrial fibrillation prior to the road traffic accident. (2) She would have developed atrial fibrillation even had she not suffered the road traffic accident. (3) She had not suffered harm although she was in atrial fibrillation as it was a well-tolerated common arrhythmia and she was doing well with medical management.
We acknowledged that it was possible that she may have had undiagnosed atrial fibrillation prior to the road traffic accident. However, there was no past medical history of this. Also, we note that prior to the road traffic accident, there were no symptoms of palpitation which she experienced with the documented episodes of paroxysmal atrial fibrillation.
We were impressed by the time course of the onset of the atrial fibrillation occurring immediately after the chest trauma. Sternal fracture in isolation without cardiac injury rarely results in atrial fibrillation but it is described and is more common in the elderly. Chest trauma may initiate the onset of atrial fibrillation in those more prone to it. We found that on the balance of probability, the chest trauma did cause atrial fibrillation. We noted that the client was clinically well at the time of examination but that the atrial fibrillation could potentially cause complications as could the medications used to treat it.
Case Verdict – The Client Has A Claim
We, therefore, found that not only had the trauma caused atrial fibrillation in this case but that the atrial fibrillation on the balance of probability could lead to harm.
Case Study 3 – Clinical Negligence
It is routine to anticoagulate patients following mechanical heart valve replacement and Warfarin (which has been used as a rat poison) is usually employed. The level of warfarinisation is important as if is too much bleeding complications may occur (as in the rats) and if too low the valve may get thrombus and embolic phenomena may occur. The level of warfarinisation is monitored by a bleeding time blood test called International Normalised Ratio (INR). In the non-treated person INR=1.0 and as the warfarin dose is increased it becomes elevated. At twice the baseline (INR=2.0).
A 55-year-old woman underwent open heart surgery with a mechanical aortic valve designed to function with less postoperative anticoagulation. This valve is advertised as having a decreased risk of thromboembolic complication and therefore less anticoagulation may be used in the postoperative period. In the six-month period following the heart surgery, the client described intermittent palpitation.
Her ECG on occasion showed sinus rhythm and on other occasions showed atrial fibrillation in this 6-month postoperative period. As per the advised protocol for this type of mechanical heart valve, the Warfarinisation was decreased 3 months after the open heart operation. Nine months after the heart operation the client suffered a left-sided embolic injury. Her warfarinisation was then increased.
The client complained that the Warfarin medication had been decreased too low for use in a mechanical heart valve and that this represented a failure of duty of care. This failure of duty of care then caused an embolic injury.
We found that the plan to reduce the level of anticoagulation was reasonable as there was trial evidence and expert guidelines supporting this approach for this specific type of mechanical valve type. Many cardiac surgeons would use the lower INR level to manage this valve type postoperatively. However, the protocol was predicated upon the postoperative normal sinus rhythm.
It was not possible to ascertain how much atrial fibrillation had occurred postoperatively or whether atrial fibrillation had been present in the months before the embolic event as no attempt had been made to document the postoperative heart rhythm over a prolonged period. We found evidence of postoperative atrial fibrillation. The evidence would have been consistent with paroxysmal atrial fibrillation occurring for several months after open heart surgery.
On balance, we found this lack of curiosity about the heart rhythm to be a failure in duty of care in this case. There was evidence on the balance of probability that there had been significant postoperative atrial fibrillation and on the balance of probability, this had contributed to the embolic event.
Case Verdict – The Client Has A Claim
We found that reducing the warfarinisation before establishing that the client was in normal sinus rhythm represented a failure in duty of care.
Want to Discuss Your Clinical Negligence Claim with Mr Ridley?
Mr Paul Ridley is a Consultant Cardiothoracic Surgeon who retired from the Royal Stoke University Hospital in October 2022 after 25 years in the position. He is an expert in adult heart surgery, mitral valve repair, surgery for atrial fibrillation, coronary artery bypass and thoracic trauma.
Mr Ridley has been undertaking medico-legal reporting since 2000 undertaking 10-20 reports a year dealing with predominately complex serious injury and medical negligence. His Claimant – Defendant – Joint ratio is approximately 80:15:5 and he has attended trial on 2 occasions.
To contact Mr Ridley for any enquires email email@example.com